title: [Measurement of myocardial blood flow using N-13 ammonia dynamic PET-theory and methodology].
abstract: Positron emission tomography (PET) offers the potential capability of noninvasive measurement of regional myocardial blood flow (RMBF) in man. Because N-13 ammonia exhibits properties which to some extent resemble those of the radioactive microsphere, we developed a first-pass flow method for noninvasive measurement of RMBF. In the present method, RMBF was determined by dividing myocardial activity at time T by arterial input integrated from the injection start to that time, where time T is the endpoint of first circulation of N-13 ammonia. Also in the present method a time-activity curve of left atrium was used as the arterial input function to make the procedure totally noninvasive. To validate the present method, we compared it with the compartment analysis. 5 patients with hypertrophic cardiomyopathy (HCM) and with a considerably thickened ventricular wall, were selected for the comparison between the first-pass flow method and the compartment analysis. The relationship of RMBFs by the two methods was y = 1.8 + 1.097x-0.002037x2 (n = 30, SEE = 5.5), where x (ml/min/100 g) was obtained by the compartment analysis, while y (ml/min/100 g) by the first-pass flow method. The result indicated that both were almost identical in physiological flow range (less than 100 ml/min/100 g), but that the first-pass flow method underestimated RMBF in the higher flow range due to venous leakage of N-13 ammonia. As the conclusion, we could at least measure RMBF of HCM patient in the physiological flow range by the present method. The future extension of the method was discussed.
authors.affiliation: Division of Accelerator Research, National Institute of Radiological Sciences, Chiba.
authors.forename: M
authors.initials: M
authors.lastname: Endo
authors.forename: K
authors.initials: K
authors.lastname: Yoshida
authors.forename: T
authors.initials: T
authors.lastname: Himi
authors.forename: A
authors.initials: A
authors.lastname: Kagaya
authors.forename: H
authors.initials: H
authors.lastname: Fukuda
authors.forename: T
authors.initials: T
authors.lastname: Iinuma
authors.forename: T
authors.initials: T
authors.lastname: Yamasaki
authors.forename: Y
authors.initials: Y
authors.lastname: Tateno
authors.forename: Y
authors.initials: Y
authors.lastname: Masuda
authors.forename: Y
authors.initials: Y
authors.lastname: Inagaki
mesh_terms: D000641:Ammonia; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging / Q000503:physiopathology; D003326:Coronary Circulation; D006801:Humans; D008954:Models, Biological; D008955:Models, Cardiovascular; D009590:Nitrogen Radioisotopes; D014055:Tomography, Emission-Computed / Q000379:methods*
chemical_list: D009590:Nitrogen Radioisotopes; D000641:Ammonia